Caliper



H. D. PETCH April 14, 1953 CALIPER Filed May 26, 1950 JNVENTOR.

zf mz Patented Apr. 14, 1953 UNITED STATES arena OFFICE GALIPER HowardfDeweyliPetch, Greenfield, Mass., assignor .oii-twenty-lfiye per cent to LawrenceW; Skinner, :Chicopee andtenrper cent to- Charles. Bunga-y,

'ApplicationMay 26, 1950, Serial No. 164,586

'LQIaim.

"My invention relates to improvementsin calipers used to measureinternal and external diam- -"eters or "calibers or cylindrical pieces and is directed more particularly to the provision of a type o'f single instrument which can serve for obtaining: both internal and external measure- "ments as desired The principal object of myinvention' isdirected "to -provide a' novel and improved construction in calipersconsisting in precision caliper arms having "adjustable caliper fingers which may serve to obtain'both outside and inside measurements asmay be desired, and there is the further provision of a unique-construction which will eliminate the now presentobjectionable. inconveniences, same being one which will operatewith amaximum-amountjof'ease an'dwith a minimum degree of eiiort;

One of the primary purposes of my invention is to provide structuraland operational improvements in devices'of'the class'towhich reference has been made, Whichimprovements not only simplify the structureas'such but also provide impoltant'distinct advantagesin strength, dura- 'bility and the like.

With the above primary object in'view, it is another object of my invention to provide a con- 'struction of the above described character .in which 'the number of operating parts is greatly reduced and which is compact in accordance with "the demands'and desires of purchasers aswell as of manufacturers andwhich isnotionlydistinctive in its appearance and practical Lin its value but alsoreliable in its operation-and efficient inits use.

3 is a still"further'objectitoprovide a .device which is constructed of relatively simple parts, same being adapted to be readily assembled and whichwhen once assembled, "are positively and I securely retained in operativerelationship.

Other prime objects of myinvention include: first, theprovision of a simplified construction and arrangement of parts'in calipers which is strong, durable and compact in its structure; second, the securement of a higher degree of accuracy in the manner of worhperformedtherewith than has heretofore heenpossibie withiprior devices known'in the art; 'thir'd,the attainment of a flexibility or a'eapahilityoi easy adjustment by which a large variety of work can be produced byimeans of the samedevice; fourth, thaachievement of a greater ease in adjustment and repairs; fifth, the provision of an inproved caliper which may be made more economically and with fewer operations in the manufacture of its parts, as

2, well as in the assembly of the same, tha n;.prior devices knownintthe1art;;anaesixth;theprovision offisuch otheriimprcvements in and relatingto calipersofnthe type ab'oveireferred to. asare here- 1 inafter describedi'and iclaimed.

My invention also Icon'sists in :certain :new and original features of construction'andiconihination of parts 'hereina'iter se't forth andclaim'ed inconjunction with therannexed idrawings whichillustrate a certain Jform ofaienibodiment thereof, which form is deemed' preierableand.isaspecific disclosure for the purpose of illustrating a single 'embodiment oi the'inventionifby way OfT-EIIliGXEJXlpie since the same has lloeenffound in practice to give satisfactory andtrelia'bleiresults .Itiis to-he 1 understood, 'however, that the various .parts iof which the invention consists ean bewariously changed within "the scope'of "the appended claim without departing from thebroa'd aaspects and "spirit of the 5 invention and that the :1 invention: is not to be limited to the precise arrangementiand organization of Who 'instrumentalities as herein shown and described.

All of the above cited objec'ts I 'accomplish'by "means of such structure and relative farrange- -m'erit "of parts thereof,=as will an appear by a perusal of the description below andhy various specific *features which Will be .hereinafter set forth. To theseahove and other ends and with the foregoing and various other rand ancillary features -anel -advantages and other objects ofmy invention as will i become :more" readily apparent as the description proceeds, my invention :con-

sists in certainnc'velfeatures of'-construction=and the combinationand-arrangementparts as will be hereinafter more "particularly pointed out in the claim hereunto annexed an dlmore :fully described and rferred toin connection with the accompanying drawings wherein:

Fig. 1 is-a top plan viewofthe devicetof my invention; a

Fig. 2 L is a side *elevational view of the device shown in Fig. 1; and

Fig. "'3' is a top plan View of apair of external caliper fingers which are interchangeable :with the internal caliper fingers shown-in Figs. 1 and2. in the following de's criptiorr and claim, various details will be identified by specific names :for convenience. 'Tihese names,xhowever, are intended to be as generic in their application as the art will'permit.

Referring now to the dra'wingsmore iii-detail in which similar characters of reference indicate corresponding parts in the several figures, and referring more particularly to the preferred form of my invention selected for illustrative purposes, I have shown a housing or body 4 having a pair of outwardly extending spaced apart arm members 6 and 1 extending from a side thereof, as shown in Fig. 1.

A central bore 8 extends through the .body 4 and is adapted to receive a protruding neck member I6 of an indicator generally indicated by the numeral I2 and including, .in addition to the aforementioned neck member [0, an indicator body member l4, a dial 15, a crystal IS, a bezel I! and a pointer It. The indicator I2 is of the well known construction.

The neck member ID has an outermost end portion 20 from which outwardly extends the'tonventional indicator contact face 22, as shown in Fig. 1.

A set screw 24 extends through the body 4 and may be adjusted so as to firmly hold the neck member ID relative the body 4 in any desired position.

The arm member 6 is provided with a-slot- 36 extending transverselytherethrough in which one extremity of a lever arm 32 is held in pivotal relation with the arm member 6 by means of a pivot member 34 connecting the arm member 6 and the lever arm 32.

The slot 34 is of such dimension as to permit pivotal movement of the lever arm 32 relative to and in front of the forward face of the body 4- in such manner that one surface of the lever arm 32 is in contact with member'22.

The arm member I is provided with a slot 40 extending transversely therethrough and throughout the length thereof, as may bebest observed byreference to Fig. 2 so that the free extremity-of the lever arm, opposite from the extremity which is pivoted to the arm member- 6,

is receivable therein whereby the aforementioned swinging movement of the lever arm 32 is facilitated.

A spring member 44 is'disposed in an opening 42 extending through the body 4 and in communication with the slot 40. This spring is seated between a set screw 46 and a detent 48 and exerts through the detent, a force against the free end of the leverarm.

A cam member 50'has a cammed end portion and a forked end 54. The'cammed end portion 52 is receivable in the'slot lll of the member I. r

The cammed end portion 52 is held in pivotal relation'tothe arm member 1 by a pin 56- where by the cam membertU-is swingable relative to the arm member! and'the body 4. v I

The outermost cam surface 53 of the cammed 1 'may be swung on this pivot to any desired position and held thereat by means of the tightening of said screw 62. i

The end of the arm member 6 is forked to provide aslot in which a caliper finger is receivable, same being held relative thereto by means of-ascrew 62. dd h That is to say, the calipers 60 and (Emery be swung inwardly-and outwardly to any desired predetermined position and then are locked into position by the tightening of the screws 62 and I2 respectively.

The finger is fixed relative to the arm member 6 whereas the finger 60 may be pivoted relative to the cam member 50.

If desired, the finger 60 and 10 may be interchanged With outside caliper fingers and 90, the same having lugs 82 and 92 respectively which are receivable in their respective slots as above pointed out. These may be locked in any desired position by means of the tightening screws 62 and-72 respectively.

In operating the device, to obtain an inside measurement, the pressure exerted on the ball pointed fingers when placed between the points to be measured, puts into operation the cam member 56 causing same to pivot on the pin 56, and

by reason of the eccentricity of the cammed end to exert pressure against the lever arm 32 causing a movement of the lever arm 32, which in turn forces down the indicator contact face 22 thereby putting into operation the indicator hand in the well known manner. ,1

The invention may be embodied in other specific forms without departing from the essential characteristics thereof. Hence, the present embodiments are therefore tobe considered in all respects merely as being illustrative and not as being restrictive, the scope of the invention being indicated by the appended claim rather than by the foregoing description, and all modifications and variations as fall'within the meaning and purview and range of equivalency of the appended claim are therefore intended to be embraced therein. I

What it is desired to claim and secure by Letters Patent of the United States is: I

A'gauge including the combination of an indi v cator having 'a contact face extending outwardly therefrom, a body fixed to the indicator and having a pair'of spaced fixed arms extending therefrom, a lever arm pivotally mounted on one of the fixed arms of said body at one extremity thereof and having an opposite extremity and an intermediate portion therebetween engageable with the contact face of the indicator, and a pair of caliper fingers each engageable with one of thearms of said body, one of said caliper fingers being pivotally fixed to one of the arms of said body, the other of said caliper fingers being pivotally fixed-to the other of the arms of said body and having acam'surface engageable with the free extremity of said lever arm and actuating said lever arm into and out of engagement with the-contact face of the indicator.

HOWARD DEWEY FETCH.

References Cited inthe file of this patent UNITED STATES PATENTS 

